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Showing 1 to 16 of 16 for “"Empirical Potentials"”.
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Database optimization algorithm for empirical potentials
The development for accurate and efficient empirical potential models requires years of efforts and is highly intuitional. This study provides an automated, quantitative algorithm to find the optimal empirical potential model for a pre-determined testing set of desired structure properties. We …
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The Development of Empirical Potentials From First-Principles and Application to Al Alloys
The segregation of Cu atoms at Al(110) $\Sigma 111$ and (001) $\Sigma$5 tilt grain-boundaries was studied. Cu atoms were found to segregate to asymmetric sites at the $\Sigma$11 boundary and form zig-zag planar aggregates at the interface. Segregation is dominated by atomic size and local …
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Methods for Accurately Modeling Complex Materials
… to model nanomagnetic systems, and novel empirical potentials that reproduce ab-initio data at a fraction of the computational cost. We also present a new global optimization procedure that we have implemented for computationally demanding classical potential fits.
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Atomistic modelling of precipitation in Ni-base superalloys
… work we develop a method for the training of empirical interatomic potentials to capture more elements in the alloy system. We focus on the embedded atom method (EAM) and use the Ni-Al system as a test case. Recently, empirical potentials have been developed based on results from DFT which …
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Calculations of the elastic constants of crystals as functions of pressure with applications to quartz and cristobalite
… for a crystal of any symmetry with a variety of potentials, elastic constant calculations were completed for both quartz and cristobalite using the potentials derived by Lasaga and Gibbs (1987, 1988), Tsuneyuki et al. (1988), van Beest et al. (1990) and Boisen and Gibbs (1993). Among the four …
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Development of Atomistic Potentials for Silicate Materials and Coarse-Grained Simulation of Self-Assembly at Surfaces
… evolutionary strategies for parametrization of empirical potentials, and their application in development of a charge-transfer potential for silica. An evolutionary strategy was meta-optimized for use in empirical potential parametrization, and a new charge-transfer empirical model was developed …
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Stress-mediated reaction pathways for dislocation nucleation in copper
… reaction pathway sampling methods and well-fit empirical potentials to determine the stress-dependent behavior of and atomistic mechanisms for dislocation nucleation at stresses much lower than typically accessible to atomistic techniques. We have shown that a significant range of stresses exist …
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Shear-induced homogeneous deformation twinning in FCC aluminum and copper via automistic simulation
… metals, aluminum and copper, is calculated using empirical potentials proposed by Mishin and by Ercolessi, based on the embedded atom method (EAM), and compared with published ab initio calculations. In copper close agreement is observed in the results given by the Mishin potential for both the …
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Atomistic Modeling Predictions Of Crack Tip Behavior In Silicon Carbide
… direct molecular dynamics (MD) simulations with empirical potentials, analytic models and electronic structure calculations to illuminate key crack tip mechanisms at low temperature, high temperature and under the influence of impurities. First, I use a multifaceted modeling approach, including …
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Defects and alloying in semiconductors: computational studies of clusters and surfaces
… atomic interactions are described using empirical potentials. The well-known Tersoff potential has proven to describe well the properties of group IV elements up to Ge. As Sn is also a group IV element, we have extended this potential to include parameters for Sn by developing an …
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Exploring heat transfer at the atomistic level for thermal energy conversion and management
… adequately, classical molecular dynamics with empirical potentials do not always yield accurate predictions. Then, we move to first-principles density functional theory (DFT) to compute mode-dependent phonon properties. Such simulations can well reproduce experimental values of phonon …
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Spin-Aware Neural Network Interatomic Potential for Atomistic Simulation
… accuracy, but at high cost and limited scale. Empirical potentials are faster and scale better, but cannot compare to ab initio in numerical and physical accuracy. Machine learning (ML) interatomic potentials (IPs) of recent years offer a balance: excellent phenomenology and accuracy, while …
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Thermal conductivity from first-principles in bulk, disordered, and nanostructured materials
… Typically, these are derived using empirical potentials which do not produce the correct harmonic and anharmonic behavior, necessary to accurately compute phonon frequencies and relaxation times. We obtain these derivatives from quantum mechanics through DFPT, and use them along with …
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An empirical potential for hydrogen bond energies determination of the orientation of anthracene molecules in the unit cell by means of a refractivity method: some ab initio calculations involving acetonitrile exchange reaction
Topic I An empirical potential for calculating hydrogen bonding energies is developed for systems of the type A-H--B, where A and/or B is oxygen or nitrogen. Point charge and van der Waals interaction are included in the potential. The parameters of the potential were optimized by means of a …
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Modeling and Estimation of Bat Flight for Learning Robotic Joint Geometry from Potential Fields
… in learning theory which derive analytical-empirical potential energy fields for identifying an underlying motion submanifold. We use these energy fields to optimize a compliant structure around a single degree-of-freedom elbow joint and to design rigid structures around spherical joints for …
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Plastic Deformation in Complex Crystal Structures
… embrittlement of steel. Materials for which empirical potentials can provide more insight than linear elasticity are explored with the example of ionic materials. This is done with a Peierls dislocation configuration and a molecular statics energy calculation. A simple model built …